Here’s the thing though: a lot can go wrong on the Rover’s descent. The big question is whether the soft landing that NASA engineers have worked on for years will actually happen, given Mars’ thin atmosphere. The landing sequence calls for the deployment of a gigantic parachute, a heat shield that burns away at 3,000 degrees Fahrenheit, a detachable landing crane and booster rockets, all of which are needed to slow the craft down from 13,000 mph in 7 minutes to a speed that can facilitate the aforementioned soft landing. There’s an awful lot of variables in that mix — if one thing fails, all bets are off. (Space.com posted a timeline on past Mars expeditions. The success rate is not high.) Adding to the suspense, it takes 14 minutes for the signal from the Rover to get to Earth.

A soft landing would mean that the Curiosity Rover can get on with its work, which includes examining and reporting back on the weather, geology and radiation levels on the red planet. One key question that it could help answer, as Wheaton and Shatner state in their respective videos, is whether there was ever life on Mars.

And, in the off chance you’re not one of the 1.2 million-plus people that have seen NASA’s “7 minutes of terror” video, here’s your chance to catch up and get ready for Sunday night’s main event.